Lemuria.

Lemuria, or Limuria, was a continent proposed in 1864 by zoologist Philip Sclater, theorized to have sunk beneath the Indian Ocean, later appropriated by occultists in supposed accounts of human origins. The theory was discredited with the discovery of plate tectonics and continental drift in the 20th century.

Lemuria : the lost continent of the Pacific by Cervé Wishar Spenle

The Lost Civilization of Lemuria. The Rise and Fall of the World's Oldest Culture Joseph Frank

The Lost Continent of Mu James Churchward

The Lost Land of Lemuria. Fabulous Geographies, Catastrophic Histories Sumathi Ramaswamy

The Lost Lemuria with 2 maps showing distribution of land areas at ... by W. Scott Elliot (1904)

The Mountain Tops Of Lemuria (1901)